Abstract:

The invention relates to a composition containing a particulate solid, an
organic or aqueous medium, and a copolymer containing less than 25 mol %
of residues of monomers comprising a dicarboxylic acid, or anhydride
thereof. The invention further relates to novel copolymers, and the use
of the copolymers as a dispersant.

Claims:

1. A copolymer comprising a polymer derived from (a) monomer (A), and (b)
monomer (B), a dicarboxylic acid or anhydride thereof, which contains
less than 25 mol % of monomer (B),wherein at least a portion of the
anhydride or dicarboxylic acid groups derived from monomer (B) are
subsequently reacted with at least one amine selected from the group
consisting of:(i) a compound containing at least one tertiary or
heterocyclic amine site and at least one additional group capable of
reacting with dicarboxylic acid, or anhydride functional groups, and(ii)
a polyetheramine.

2. The copolymer of claim 1, wherein the copolymer has a number average
molecular weight of 1000 to 50,000.

3. (canceled)

4. The copolymer of claim 1, wherein the copolymer contains monomer (B) at
less than 20 mol %.

9. The copolymer of claim 1, wherein the copolymer is derived from an
α-olefin and maleic anhydride.

10. The copolymer of claim 1, wherein the copolymer is derived from a
vinyl aromatic monomer and maleic anhydride.

11. The copolymer of claim 1, wherein the compound containing at least one
tertiary or heterocyclic amine site is selected from the group consisting
of a dialkylaminoalkylamine, a substituted dialkylaminoalkylamine, an
aminoalkyl substituted nitrogen containing aromatic heterocycle, a
dialkylaminoalkyl alcohol, a hydroxyalkyl substituted nitrogen containing
aromatic heterocycle, and mixtures thereof.

12. The copolymer of claim 11, wherein the compound containing at least
one tertiary or heterocyclic amine site is selected from the group
consisting of a dialkylaminoalkylamine, a substituted
dialkylaminoalkylamine, and mixtures thereof.

13. The copolymer of claim 11, wherein the dialkylaminoalkylamine is
dimethylaminoethylamine, diethylaminopropylamine, or
dimethylaminopropylamine.

14. The copolymer of claim 1, wherein the polyetheramine is a
poly(C2-4-alkylene oxide), or mixtures thereof.

15. The copolymer of claim 14, wherein the polyetheramine contains less
than 60% by weight ethylene oxide relative to the total weight of a poly
(C2-4-alkylene oxide) chain.

16. The copolymer of claim 1, wherein the copolymer is quaternised.

17. (canceled)

18. The copolymer of claim 1, wherein the compound containing at least one
tertiary or heterocyclic amine site reacts with up to 70% of monomer (8)
groups.

19. The copolymer of claim 1, wherein the compound containing at least one
tertiary or heterocyclic amine site reacts with up to 35% of monomer (B)
groups of the copolymer.

20. The copolymer of claim 1, wherein the polyetheramine reacts with at
least 30% of monomer (B) groups of the copolymer.

21. A composition comprising a particulate solid, an organic medium and a
copolymer comprising a polymer derived from (a) monomer (A), and (b)
monomer (B), dicarboxylic acid or anhydride thereof, which contains less
than 25 mol % of monomer (B),wherein at least a portion of the anhydride
or dicarboxylic acid groups derived from monomer (B) are subsequently
reacted with at least one amine selected from the group consisting of:(i)
a compound containing at least one tertiary or heterocyclic amine site
and at least one additional group capable of reacting with dicarboxylic
acid, or anhydride functional groups, and(ii) a polyetheramine.

22. A composition comprising a particulate solid, an aqueous medium and a
copolymer comprising a polymer derived from (a) monomer (A), and (b)
monomer (B), dicarboxylic acid or anhydride thereof, which contains less
than 25 mol % of monomer (B),wherein at least a portion of the anhydride
or dicarboxylic acid groups derived from monomer (B) are subsequently
reacted with at least one amine selected from the group consisting of:(i)
a compound containing at least one tertiary or heterocyclic amine site
and at least one additional group capable of reacting with dicarboxylic
acid, or anhydride functional groups, and(ii) a polyetheramine.

23. The use of the copolymer of claim 1 as a dispersant.

Description:

FIELD OF INVENTION

[0001]The invention relates to a composition containing a particulate
solid, an organic or aqueous medium, and a copolymer containing less than
25 mol % of residues of monomers comprising a dicarboxylic acid, or
anhydride thereof. The invention further relates to novel copolymers, and
the use of the copolymers as a dispersant.

BACKGROUND OF THE INVENTION

[0002]Many coating properties such as colour intensity, opacity and gloss
depend upon the extent of aggregation or flocculation of pigment
particles (or other particulate materials) within the coating. Colour is
normally introduced into a coating formulation by addition of a pigment
dispersion in solvent containing a high concentration of pigment. The
pigment dispersion is generally produced by one of a variety of milling
techniques to break up the aggregates of pigment particles and reduce the
average particle size. Milling is often carried out in the presence of
some polymeric material which is present to stabilize the dispersion and
minimize flocculation of the dispersed particles.

[0003]It can often be advantageous to be able to use one colour
concentrate for letdown into a variety of different binder systems.
However, the polymeric material present in the colour concentrate can
give rise to problems if it is not compatible with the coating binder.
For example, when nitrocellulose is utilised as a pigment grinding medium
in a polyamide binder system, there may be compatibility problems leading
to reduced gloss and colour strength.

[0004]U.S. Pat. No. 6,406,143 discloses a graft copolymer of
styrene-maleic anhydride reacted with a polyetheramine. The graft
copolymer is described as suitable for use as an ink-jet dispersant.

[0005]U.S. Pat. Nos. 5,705,603, 5,391,632; and European Patent
applications EP 324 547 A2, and EP 606 055 B1, all disclose a
polyetheramine copolymer containing α,β-unsaturated
dicarboxylic acids or anhydrides. The dicarboxylic acids or anhydrides
groups are reacted such that they contain 20-80 mole percent of a mixture
of (i) unreacted anhydrides, imides, amides, half-acid-amides. The imides
and amides are derived from an alkyl amine containing 6 to 40 carbon
atoms.

[0006]Japanese Patent publication JP 2006028252 A (published on Feb. 2,
2006, and assigned to Ajinomoto Co. Inc.) discloses an amino-group
containing maleic acid copolymer useful as a dispersant. The copolymer
contains a ratio of constituent (A) to constituent (B) of 1:3 to 3:1.

[0007]Therefore, there is a need for pigment dispersants which can
generate stable colour concentrates and provide acceptable or improved
coating properties when used in a range of different ink and coating
binders such as nitrocellulose, polyamide and polyurethane.

SUMMARY OF THE INVENTION

[0008]In one embodiment, the invention provides a copolymer comprising a
polymer derived from (a) monomer (A), and (b) monomer (B), a dicarboxylic
acid or anhydride thereof, which contains less than 25 mol % of monomer
(B) (based on the combined mole percent of (A) and (B)),

[0009]wherein at least a portion of the anhydride or dicarboxylic acid
groups derived from monomer (B) are subsequently reacted with at least
one amine selected from the group consisting of:

[0010](i) a compound containing at least one tertiary or heterocyclic
amine site and at least one additional group capable of reacting with
dicarboxylic acid, or anhydride functional groups, and

[0011](ii) a polyetheramine.

[0012]In one embodiment, the copolymer comprises groups derived from both

[0013](i) a compound containing at least one tertiary or heterocyclic
amine site and at least one additional group capable of reacting with
dicarboxylic acid, or anhydride functional groups, and

[0014](ii) a polyetheramine.

[0015]In one embodiment, the invention provides a composition comprising a
particulate solid, an organic or aqueous medium and a copolymer as
defined above.

[0016]In one embodiment, the invention provides a composition comprising a
particulate solid, an organic or aqueous medium and a copolymer
obtained/obtainable by reacting:

[0017](1) (a) monomer (A) (such as vinyl aromatic monomer or an
α-olefin), and (b) monomer (B), a dicarboxylic acid or anhydride
thereof to form a copolymer, wherein the copolymer contains less than 25
mol % of monomer (B);

[0018](2) reacting the copolymer of (1) with at least one amine selected
from the group consisting of:

[0019](i) a compound containing at least one tertiary or heterocyclic
amine site and at least one additional group capable of reacting with
dicarboxylic acid, or anhydride functional groups, and

[0020](ii) a polyetheramine.

[0021]In one embodiment, the invention provides for the use of the
copolymer as defined above as a dispersant.

[0022]In one embodiment, the invention provides for the use of the
copolymer as defined above as a dispersant in the composition disclosed
herein.

[0027]In one embodiment, monomer (A) includes an α-olefin, a vinyl
aromatic monomer, or mixtures thereof.

[0028]In one embodiment, the copolymer is derived from an α-olefin
and maleic anhydride (or maleic acid).

[0029]In one embodiment, the copolymer is derived from a vinyl aromatic
monomer and maleic anhydride (or maleic acid).

[0030]The compound containing at least one tertiary or heterocyclic amine
site typically reacts with up to 70%, or up to 50%, or up to 35% of
monomer (B) groups of the copolymer. The minimum percentage of monomer
(B) groups reacting with the compound containing at least one tertiary or
heterocyclic amine site typically includes at least 5%, or at least 8%,
or at least 10%, or at least 14% of monomer (B) groups of the copolymer.

[0031]The polyetheramine typically reacts with at least 10%, or at least
30%, or at least 50%, or at least 65% of monomer (B) groups of the
copolymer. The maximum percentage of monomer (B) groups reacting with the
polyetheramine is typically not more than 95%, or not more than 92%, or
not more than 90%, or not more than 86%. In one embodiment, the
percentage of monomer (B) groups reacting with the polyetheramine is in
the range of 65% to 86%.

[0032]Optionally, a portion of monomer (B) further reacts with an alcohol
and/or an amine other than (i) the compound containing at least one
tertiary or heterocyclic amine, and (ii) the polyetheramine. The monomer
(B) may react with another amine at 0% to 20%, or 0%, to 10%, or 0% to
5%. In one embodiment, monomer (B) is not further reacted with an alcohol
and/or an amine other than (i) the compound containing at least one
tertiary or heterocyclic amine.

[0033]In one embodiment, the copolymer contains a portion of monomer (B)
is not reacted with an amine other than (i). The portion of monomer (B)
that does not react with an amine other than (i) may be 0% to 20%, or 0%,
to 10%, or 0% to 5%.

Monomer (A)

[0034]In one embodiment, monomer (A) is a vinyl aromatic monomer. Examples
of a suitable vinyl aromatic monomer include styrene (also referred to as
ethenylbenzene), substituted styrene or mixtures thereof. Examples of a
suitable substituted styrene include α-methylstyrene,
para-methylstyrene (also referred to as vinyl toluene),
para-tert-butylstyrene, α-ethylstyrene or mixtures thereof. In one
embodiment, the vinyl aromatic monomer is styrene.

[0035]In one embodiment, the α-olefin is derived from the formula
H2C═CHR1, wherein R1 is a hydrocarbyl group (for
example an alkyl radical containing 1 to 18, or 1 to 10, or 1 to 6, or 1
to 3 carbon atoms). The hydrocarbyl group includes an alkyl radical that
has a straight chain, a branched chain or mixtures thereof. Examples of a
comonomer include propylene, 1-butene, 1-hexene, 1-octene,
4-methyl-1-pentene, 1-decene or mixtures thereof. In one embodiment, the
comonomer includes 1-butene, propylene or mixtures thereof. Examples of
the olefin copolymers include ethylene-propylene copolymers,
ethylene-1-butene copolymers or mixtures thereof.

[0036]In one embodiment, the α-olefin includes a comonomer, wherein
the comonomer contains a number of carbon atoms in ranges of 6 to 40, or
10 to 34, or 14 to 22. Examples of an α-olefin include 1-decene
1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene,
1-hexadecene, 1-heptadecene 1-octadecene, 1-nonadecene, 1-eicosene,
1-doeicosene, 2-tetracosene, 3-methyl-1-henicosene, 4-ethyl-2-tetracosene
or mixtures thereof. Useful examples of an α-olefin include
1-pentadecene, 1-hexadecene, 1-heptadecene 1-octadecene, 1-nonadecene or
mixtures thereof. The α-olefin is often commercially available as
mixtures especially as C16-C18.

[0039]In one embodiment, the compound containing at least one tertiary or
heterocyclic amine may be a dialkylaminoalkylamine, a substituted
dialkylaminoalkylamine, or mixtures thereof.

[0040]The dialkylaminoalkylamine may be represented by the formula
R2(R3)NR4NH2 wherein R2 and R3 are
independently C1-C6 alkyl moieties. R2 and R3 may be taken
together to form a cyclic structure containing 5 to 8 carbon atoms.
R4 includes C1 to C12 linear or branched alkylene.

[0041]Examples of a dialkylaminoalkylamine include
dimethylaminoethylamine, diethylaminopropylamine, or
dimethylaminopropylamine.

[0042]The substituted dialkylaminoalkylamine may be represented by the
formula R2(R3)NR4NHR5, wherein R2, R3 and
R4 are defined above, and R5 is an optionally substituted
linear or branched hydrocarbyl group.

[0046]The polyetheramine may be a mono-functional polyetheramine, or
mixtures thereof.

[0047]In one embodiment, the polyetheramine is a poly(C2-4-alkylene
oxide), or mixtures thereof. The polyetheramine may contain less than
60%, or less than 40%, or less than 20% by weight ethylene oxide relative
to the total weight of a poly (C2-4-alkylene oxide) chain.

[0048]The alkylene moiety of the (C2-4-alkylene oxide) group may be
linear or branched. In one embodiment, the alkylene moiety is branched.
The alkylene moiety may be obtained by (co)polymerisation of alkylene
oxides such as ethylene oxide, propylene oxide and butylene oxide or from
tetrahydrofuran. Copolymers may be random or block copolymers.

[0049]In one embodiment, the polyether chain is obtainable from propylene
oxide. The polyether chain of the polyetheramine may also be obtainable
from a poly(C2-4-alkylene oxide) mono-C1-10-alkyl ether. The
(C2-4-alkylene oxide) mono-C1-10-alkyl ether may be a methyl or
butyl ether.

[0050]The number-average molecular weight of the polyetheramine may not be
greater than 10,000, or not greater than 4000, or not greater than 2500.
The number-average molecular weight of the polyetheramine may not be less
than 300, or not less than 550, or not less than 800. In one embodiment,
the polyetheramine has a number average molecular weight of 550 to 2500.

[0051]The polyetheramines used can be prepared, for example, by reductive
amination of monoalkyl ethers of polyalkylene glycols.

[0052]Polyetheramines may also be obtained from reaction of a poly
(alkylene oxide) monoalkyl ether with acrylonitrile and subsequent
reduction with hydrogen.

[0053]Moreover, polyetheramines are obtainable by reaction of polyethers
with phosgene or thionyl chloride and subsequent amination to give the
polyetheramine.

[0054]A suitable source of polyetheramines is the Jeffamine® M series
of monoamines or Surfonamine® products available from Huntsman
Corporation.

[0055]The polyetheramine is reacted with the copolymer to form either
amide links, imide links, or a mixture of amide and imide links.

[0058]The compound containing at least one tertiary or heterocyclic amine
may be partially or wholly quaternised. Quaternising agents are known in
the art. Examples of quaternising agents include alkyl halides, aralkyl
halides, dialkyl carbonates, dialkyl sulphates or epoxides. In one
embodiment, the quaternising agents include dimethyl sulphate, benzyl
chloride, propylene oxide or styrene oxide. In one embodiment, the
copolymer is quaternised, and in another embodiment the copolymer is not
quaternised.

Process

[0059]The backbone of the copolymer derived from monomer (A), and monomer
(B) may be prepared by techniques known in the art. A copolymer derived
from (a) monomer (A), and (b) monomer (B), a dicarboxylic acid or
anhydride thereof, are known. In addition, the reaction of monomer (B)
with amines and alcohols are well known. U.S. Pat. No. 5,705,603
describes a general procedure for preparing a copolymer derived from (a)
monomer (A), and (b) monomer (B), a dicarboxylic acid or anhydride
thereof reacted with an amine.

[0060]The copolymer of the present invention may be prepared by reacting
the copolymer derived from (a) monomer (A), and (b) monomer (B), a
dicarboxylic acid or anhydride thereof, which contains less than 25 mol %
of monomer (B), wherein at least a portion of the anhydride or
dicarboxylic acid groups derived from monomer (B) are subsequently
reacted with at least one amine selected from the group consisting of:

[0061](i) a compound containing at least one tertiary or heterocyclic
amine site and at least one additional group capable of reacting with
dicarboxylic acid, or anhydride functional groups, and (ii) a
polyetheramine.

[0062]Optionally, a portion of monomer (B) further reacts with (iii) an
alcohol and/or (iv) an amine other than (i) the compound containing at
least one tertiary or heterocyclic amine, and (ii) the polyetheramine.

[0063]Reaction with (i), (ii) and optional components (iii) and/or (iv)
may be carried out at a temperature in the range of 20° C. to
250° C., or 60° C. to 200° C.

[0064]Typically, a reaction temperature of less than 100° C. will
typically favour formation of amides. Whereas, a reaction temperature of
150° C. or greater will typically favour formation of imides.

[0065]When a portion of a primary amine from (iii) is reacted, the
resultant copolymer may contain amide or imide groups.

[0066]The reactions may be carried out in the bulk or in the presence of a
solvent. A solvent, if used, may be aliphatic or aromatic.

[0067]A suitable solvent may be chosen from aromatic hydrocarbons, such as
toluene and xylene, aliphatic hydrocarbons, alkyl esters of alkane
carboxylic acids, dialkyl ketones and dialkyl and cyclic ethers such as
diethyl ether and tetrahydrofuran.

[0069]In one embodiment, the copolymer as defined above is a dispersant.

[0070]The copolymer in different embodiments is present in a composition
of the invention in a range selected from 0.1 wt. % to 50 wt. %, or 0.25
wt. % to 35 wt. %, and 0.5 wt. % to 30 wt. %.

[0071]The particulate solid present in the composition may be any
inorganic or organic solid material which is substantially insoluble in
the organic medium. In one embodiment, the particulate solid is a
pigment.

[0072]In one embodiment, the composition of the invention provides a paint
or ink including a particulate solid, an organic liquid, a binder and a
copolymer as described herein.

[0073]In one embodiment, the solid is an organic pigment from any of the
recognised classes of pigments described, for example, in the Third
Edition of the Colour Index (1971) and subsequent revisions of, and
supplements thereto, under the chapter headed "Pigments". Carbon black,
although strictly inorganic, behaves more like an organic pigment in its
dispersing properties. Examples of organic pigments are those from the
azo, disazo, condensed azo, thioindigo, indanthrone, isoindanthrone,
anthanthrone, anthraquinone, isodibenzanthrone, triphendioxazine,
quinacridone and phthalocyanine series, especially copper phthalocyanine
and its nuclear halogenated derivatives, and also lakes of acid, basic
and mordant dyes. In one embodiment, the organic pigments are
phthalocyanines, especially copper phthalocyanines, monoazos, disazos,
indanthrones, anthranthrones, quinacridones and carbon blacks.

[0076]The organic medium present in the composition of the invention in
one embodiment is a plastics material and in another embodiment an
organic liquid. The organic liquid may be a non-polar or a polar organic
liquid, although a polar organic liquid is typically used. By the term
"polar" in relation to the organic liquid, it is meant that an organic
liquid is capable of forming moderate to strong bonds as described in the
article entitled "A Three Dimensional Approach to Solubility" by Crowley
et al. in Journal of Paint Technology, Vol. 38, 1966, at page 269. Such
organic liquids generally have a hydrogen bonding number of 5 or more as
defined in the abovementioned article.

[0077]Examples of suitable polar organic liquids are amines, ethers,
especially lower alkyl ethers, organic acids, esters, ketones, glycols,
alcohols and amides. Numerous specific examples of such moderately
strongly hydrogen bonding liquids are given in the book entitled
"Compatibility and Solubility" by Ibert Mellan (published in 1968 by
Noyes Development Corporation) in Table 2.14 on pages 39-40 and these
liquids all fall within the scope of the term polar organic liquid as
used herein.

[0079]Examples of organic liquids, which may be used as polar organic
liquids are film-forming resins such as inks, paints and chips for use in
various applications such as paints and inks. Examples of such resins
include polyurethanes, polyamides, such as Versamid® and Wolfamid®,
and cellulose ethers, such as ethyl cellulose and ethyl hydroxyethyl
cellulose, nitrocellulose and cellulose acetate butyrate resins,
including mixtures thereof. Examples of paint resins include short oil
alkyd/melamine-formaldehyde, polyester/melamine-formaldehyde,
thermosetting acrylic/melamine-formaldehyde, long oil alkyd, polyether
polyols and multi-media resins such as acrylic and urea/aldehyde. In one
embodiment, examples of such resins include polyurethanes, polyamides,
and cellulose ethers.

[0080]The organic liquid may be a polyol, that is to say, an organic
liquid with two or more hydroxy groups. In one embodiment, polyols
include α-omega diols or α-omega diol ethoxylates.

[0082]In one embodiment, the organic liquid includes at least 0.1% by
weight, or 1% by weight or more of a polar organic liquid based on the
total organic liquid.

[0083]The organic liquid optionally further includes water. In one
embodiment, the organic liquid is free of water.

[0084]When the organic liquid contains water, the amount present in one
embodiment is not greater than 70%, or not greater than 50%, or not
greater than 40% by weight based on the amount of organic liquid.

[0085]The plastics material may be a thermoset resin or a thermoplastic
resin. The thermosetting resins useful in this invention include resins
which undergo a chemical reaction when heated, catalysed, or subject to
UV or electron beam radiation and become relatively infusible. Typical
reactions in thermosetting resins include oxidation of unsaturated double
bonds, reactions involving epoxy/amine, epoxy/carbonyl, epoxy/hydroxyl,
polyisocyanate/hydroxy, amino resin/hydroxy moieties, free radical
reactions or polyacrylate, cationic polymerization or epoxy resins and
vinyl ether, or condensation of silanol.

[0087]In one embodiment, thermoplastic resins include polyolefins,
polyesters, polyamides, polycarbonates, polyurethanes, polystyrenics,
poly(meth)acrylates, celluloses and cellulose derivatives. Said
compositions may be prepared in a number of ways but melt mixing and dry
solid blending are typical methods.

[0089]The compositions typically contain from 1 to 95% by weight of the
particulate solid, the precise quantity depending on the nature of the
solid and the quantity depending on the nature of the solid and the
relative densities of the solid and the polar organic liquid. For
example, a composition in which the solid is an organic material, such as
an organic pigment, in one embodiment contains from 15 to 60% by weight
of the solid whereas a composition in which the solid is an inorganic
material, such as an inorganic pigment, filler or extender, in one
embodiment contains from 40 to 90% by weight of the solid based on the
total weight of composition.

[0090]The composition may be prepared by any of the conventional methods
known for preparing dispersions. Thus, the solid, the organic medium and
the dispersant may be mixed in any order, the mixture then being
subjected to a mechanical treatment to reduce the particles of the solid
to an appropriate size, for example, by ball milling, bead milling,
gravel milling or plastic milling until the dispersion is formed.
Alternatively, the solid may be treated to reduce its particle size
independently or in admixture with either, the organic medium or the
dispersant, the other ingredient or ingredients then being added and the
mixture being agitated to provide the composition.

[0091]In one embodiment, the composition of the present invention is
suited to liquid dispersions. In one embodiment, such dispersion
compositions comprise: (a) 0.5 to 40 parts of a particulate solid, (b)
0.5 to 30 parts of a copolymer described herein, and (c) 30 to 99 parts
of an organic or aqueous medium; wherein all parts are by weight and the
amounts (a)+(b)+(c)=100.

[0093]As used herein, the organic medium typically contains less than 5
wt. % or less than 2 wt. %, or less than 0.5 wt. % of water or a polar
solvent.

[0094]In one embodiment, component a) includes 0.5 to 40 parts of a
pigment and such dispersions are useful as liquid inks, paints and
mill-bases.

[0095]If a composition is required including a particulate solid and a
copolymer as described herein in dry form, the organic liquid is
typically volatile so that it may be readily removed from the particulate
solid by a simple separation means such as evaporation. In one
embodiment, the composition includes the organic liquid.

[0096]If the dry composition consists essentially of the copolymer
described herein and the particulate solid, it typically contains at
least 0.2%, at least 0.5% or at least 1.0% the copolymer described herein
based on weight of the particulate so lid.

[0097]As disclosed hereinbefore, the compositions of the invention are
suitable for preparing mill-bases wherein the particulate solid is milled
in an organic liquid in the presence of the copolymer described herein.

[0098]Thus, according to a still further embodiment of the invention,
there is provided a mill-base including a particulate solid, an organic
liquid and the copolymer described herein.

[0099]Typically, the mill-base contains from 20% to 70% by weight
particulate solid based on the total weight of the mill-base. In one
embodiment, the particulate solid is not less than 10%, or not less than
20% by weight of the mill-base. Such mill-bases may optionally contain a
binder added either before or after milling. The binder is a polymeric
material capable of binding the composition on volatilisation of the
organic liquid.

[0100]Binders are polymeric materials including natural and synthetic
materials. In one embodiment, binders include poly(meth)acrylates,
polystyrenics, polyesters, polyurethanes, alkyds, polysaccharides such as
cellulose, and natural proteins such as casein. In one embodiment, the
binder is present in the composition at more than 100 wt. % based on the
amount of particulate solid, more than 200 wt. %, more than 300 wt. % or
more than 400 wt. %.

[0101]The amount of optional binder in the mill-base can vary over wide
limits but is typically not less than 10%, and often not less than 20% by
weight of the continuous/liquid phase of the mill-base. In one
embodiment, the amount of binder is not greater than 50%, or not greater
than 40% by weight of the continuous/liquid phase of the mill-base.

[0102]The amount of dispersant in the mill-base is dependent on the amount
of particulate solid but is typically from 0.5% to 5% by weight of the
mill-base.

[0103]Dispersions and mill-bases made from the composition of the
invention are particularly suitable for use in coatings and paints both
solvent-based and water-base, especially high solids paints; inks,
especially offset, flexographic, gravure, radiation-curable, and screen
inks; non-aqueous ceramic processes, especially tape-coating,
doctor-blade, extrusion and injection moulding type processes,
composites, cosmetics, adhesives and plastics materials.

[0104]In one embodiment, the composition of the invention further includes
one or more additional known dispersants.

[0105]The following examples provide illustrations of the invention. These
examples are non exhaustive and are not intended to limit the scope of
the invention.

EXAMPLES

Comparative Examples A-D

[0106]Sartomer SMA EF40 or Sartomer SMA EF60 (both generically a styrene
maleic anhydride copolymer supplied by Sartomer) and ethyl acetate are
charged into a 250 cm3 4-neck round bottom flask, fitted with
condenser, mechanical stirrer, thermocouple, nitrogen inlet and dropping
funnel. After the SMA dissolves, Jeffamine® M2005 (a polyetheramine
commercially available from Huntsman) is added over a period of 10
minutes at room temperature whilst stirring under a blanket of nitrogen.
A small exotherm is observed. The flask is then heated and stirred at
80° C. for a minimum of 6 hours. In each case, the product
obtained is a clear yellow solution. The quantities of reagents used in
each comparative example are as detailed in the following table:

[0107]Comparative Example A (50 parts of 40.7 wt. % solution in ethyl
acetate) is charged into a 100 cm3 3-neck round bottom flask fitted
with condenser, mechanical stirrer, thermocouple and nitrogen inlet. 1.34
parts of a 10 wt. % solution of DMAPA (3-dimethylamino-1-propylamine) in
ethyl acetate is added to the flask and the resulting solution is stirred
at 80° C. under nitrogen for a total of 15 hours. The product
obtained is a clear yellow solution with solids content 45.5 wt. %.

Example 2

[0108]Comparative Example A (50 parts of 40.7 wt. % solution in ethyl
acetate) is charged into a 100 cm3 3-neck round bottom flask fitted
with condenser, mechanical stirrer, thermocouple and nitrogen inlet. 3.36
parts of a 10 wt. % solution of DMAPA in ethyl acetate is added to the
flask and the resulting solution was stirred at 80° C. under
nitrogen for a total of 13 hours. The product obtained is a clear yellow
solution with solids content 45.3 wt. %.

Example 3

[0109]Comparative Example A (50 parts of 40.7 wt. % solution in ethyl
acetate) is charged into a 100 cm3 3-neck round bottom flask fitted
with condenser, mechanical stirrer, thermocouple and nitrogen inlet.
DMAPA (0.673 parts) is added to the flask and the resulting solution was
stirred at 80° C. under nitrogen for a total of 13 hours. The
product obtained is a clear yellow solution with solids content 41.8 wt.
%.

Example 4

[0110]Comparative Example B (50 parts of 44.3 wt. % solution in ethyl
acetate) is charged into a 100 cm3 3-neck round bottom flask fitted
with condenser, mechanical stirrer, thermocouple and nitrogen inlet. A
solution of DMAPA (0.116 parts) in ethyl acetate (1.0 parts) is added and
the resulting solution was stirred at 80° C. under nitrogen for a
total of 15 hours. The product obtained as a clear yellow solution with
solids content 48.9 wt. %.

Example 5

[0111]Comparative Example B (50 parts of 44.3 wt. % solution in ethyl
acetate) is charged into a 100 cm3 3-neck round bottom flask fitted
with condenser, mechanical stirrer, thermocouple and nitrogen inlet. 2.9
parts of 10 wt. % solution of DMAPA in ethyl acetate is added and the
resulting solution was stirred at 80° C. under nitrogen for a
total of 15 hours. The product obtained is a clear yellow solution with
solids content 48.9 wt. %.

Example 6

[0112]Comparative Example C (50 parts of 40.6 wt. % solution in ethyl
acetate) is charged into a 100 cm3 3-neck round bottom flask fitted
with condenser, mechanical stirrer, thermocouple and nitrogen inlet. 1.23
parts of 10 wt. % solution of DMAPA in ethyl acetate is added and the
resulting solution was stirred at 80° C. under nitrogen for a
total of 13 hours. The product obtained is a clear yellow solution with
solids content 43.2 wt. %.

Example 7

[0113]Comparative Example C (50 parts of 40.6 wt. % solution in ethyl
acetate) is charged into a 100 cm3 3-neck round bottom flask fitted
with condenser, mechanical stirrer, thermocouple and nitrogen inlet.
3.065 parts of 10 wt. % solution of DMAPA in ethyl acetate is added and
the resulting solution was stirred at 80° C. under nitrogen for a
total of 13 hours. The product obtained is a clear yellow solution with
solids content 42.2 wt. %.

Example 8

[0114]Comparative Example C (50 parts of 40.6 wt. % solution in ethyl
acetate) is charged into a 100 cm3 3-neck round bottom flask fitted
with condenser, mechanical stirrer, thermocouple and nitrogen inlet.
DMAPA (0.613 parts) is added to the flask and the resulting solution was
stirred at 80° C. under nitrogen for a total of 14 hours. The
product obtained is a clear yellow solution with solids content of 41.8
wt. %.

Example 9

[0115]Comparative Example D (50 parts of 43.6 wt. % solution in ethyl
acetate) is charged into a 100 cm3 3-neck round bottom flask fitted
with condenser, mechanical stirrer, thermocouple and nitrogen inlet.
0.932 parts of 10 wt. % solution of DMAPA in ethyl acetate is added and
the resulting solution is stirred at 80° C. under nitrogen for a
total of 15 hours. The product obtained is a clear yellow solution with
solids content 52.9 wt. %.

Example 10

[0116]Sartomer SMA 2000 (25.0 parts) is dissolved in ethyl acetate (159.8
parts) in a 250 cm3 4-neck round bottom flask, fitted with
condenser, mechanical stirrer, thermocouple, nitrogen inlet and dropping
funnel. Jeffamine M2005 (81.5 parts) is added over a period of 30 minutes
at room temperature whilst stirring under a blanket of nitrogen. A small
exotherm is observed. After standing overnight the reaction mixture is
heated and stirred at 60° C. for 3 hours resulting in a clear
yellow solution with solids content 43.7 wt. %. 50 parts of this solution
is transferred to another flask. A solution of DMAPA in ethyl acetate (25
wt. % active, 0.68 parts) is added to the solution. The resulting
solution is stirred at 80° C. under nitrogen for a total of 15
hours. The product obtained is a clear yellow solution with solids
content 43.6 wt. %.

Example 11

[0117]is prepared in the same manner as Example 4 using the same reagents
and relative quantities. The product obtained as a clear yellow solution
with solids content 45.6 wt. %.

Example 12

[0118]100 parts of the solution of comparative Example E is added to a 250
cm3 4-neck round bottom flask fitted with condenser, mechanical
stirrer, thermocouple and nitrogen inlet. A solution of DMAPA (0.543
parts) in ethyl acetate (5.0 parts) is added and the resulting solution
is stirred at 80° C. under nitrogen for a total of 15 hours. The
solution is cooled to ambient. Benzyl chloride (0.673 parts) is added to
the reaction vessel and the mixture heated to 80° C. for 12 hours.
The quaternised product has a solids content of 42.5 wt. %.

Example 13

[0119]100 parts of the solution of comparative Example E is added to a 250
cm3 4-neck round bottom flask fitted with condenser, mechanical
stirrer, thermocouple and nitrogen inlet. A solution of 3-aminopropyl
imidazole (0.266 parts) in ethyl acetate (0.264 parts) is added and the
resulting solution is stirred at 80° C. under nitrogen for a total
of 21 hours. The product obtained is a clear yellow solution with solids
content 43.5 wt. %.

Example 14

[0120]Sartomer SMA EF40 (25.0 parts) and Jeffamine M2005 (64.1 parts) are
charged into a 3-neck round bottom flask, fitted with mechanical stirrer,
thermocouple and nitrogen inlet to form a mixture. The mixture is heated
with stirring under a nitrogen atmosphere to 110° C. and held
until the Sartomer SMA EF40 dissolves. The temperature is raised to
180° C. and maintained for 18 hours. The contents of the flask are
then cooled 70° C. and DMAPA (0.468 parts) is added. The mixture
is reheated to 180° C. and temperature maintained for a further 11
hours. The product obtained is a highly viscous orange liquid.

[0121]Black Pigment Dispersions: Black mill-bases are prepared by adding
the materials detailed in the following table to a 125 cm3 glass jar
in the order listed. The pigment loading is 25 parts and the active
content of the dispersant is 25 wt. % based on the mass of pigment used.
The mill-bases further contain 12.5 parts of Elftex®415 (a black
pigment commercially available from Cabot Corporation), 1.7 parts of
Laropal® K80 (a ketone resin commercially available from BASF), and
26.9 parts of ethanol. The table below indicates the amount ethyl acetate
and dispersant present.

[0122]In each case, the mixture is gently stirred to wet out the pigment.
125 parts of 3 mm diameter glass beads are added to the jar. The jar is
placed in a Scandex disperser model 200-K and the contents milled by
oscillatory shaking for 2 hours.

[0123]A 19.6 wt. % active nitrocellulose solution is prepared by mixing
together 126 parts of nitrocellulose DLX® 5-10 (70 wt. % active in
isopropanol, and commercially available from Nobel Enterprises) 189 parts
ethanol, and 135 parts ethyl acetate. A nitrocellulose based ink
formulation is prepared by adding 1.5 parts of a mill-base described
above to the nitrocellulose solution.

[0124]The resulting ink formulations are drawn down onto Leneta black and
white card using an automatic film applicator fitted with a number 2 K
bar. The coatings are allowed to air dry. Gloss and Haze of the coatings
are measured using a Byk Gardner 4600 Haze-gloss meter. Jetness of the
coating is visually assessed under standard D65 illumination. A drawdown
prepared from a control formulation is given an arbitrary jetness rating
of 3. The drawdowns prepared from the inks are rated relative to the
control on a scale of 1 to 5 (1=high jetness, 5=low jetness). The results
are detailed in the table below:

[0126]In each case, the mixture is gently stirred to wet out the pigment.
125 parts of 3 mm diameter glass beads were added to the jar. The jar is
placed in a Scandex disperser model 200-K and the contents milled by
oscillatory shaking for 30 minutes.

Blue Nitrocellulose (NC) Ink

[0127]Nitrocellulose DLX 3-5 is diluted to 36 wt. % active by addition of
ethanol and ethyl acetate in a weight ratio of 3:1. Blue nitrocellulose
inks are prepared by mixing the components as shown in the table.

[0128]NeoRez U-395 (supplied by NeoResins as 45 wt. % active solution in
ethanol/ethyl acetate) is diluted to a 36 wt. % active solution by
addition of ethyl acetate. Blue polyurethane inks are prepared by mixing
the components as shown in the table.

[0129]UNI-REZ 126 (supplied by Arizona Chemical) is diluted to a 36 wt. %
active solution by addition of a blend of ethanol/ethyl acetate in weight
ratio of 3/1. Blue polyamide inks are prepared by mixing the components
as shown in the table.

[0130]The blue ink formulations are drawn down onto Leneta black and white
card using an automatic film applicator fitted with a number 2 K bar. The
coatings are allowed to air dry. Gloss and Haze of the coatings are
measured using a Byk Gardner 4600 Haze-gloss meter. Colouristic
properties are visually assessed under standard D65 illumination. A
drawdown prepared from a control formulation is assigned an arbitrary
value of 0 for both colour intensity and transparency. The drawdowns
prepared from the other inks are assessed relative to the control. For
intensity positive numbers indicate stronger colour, negative numbers
weaker colour. For transparency positive numbers indicate more
transparent, negative numbers more opaque. The results are shown in the
following tables.

[0131]The data obtained from the tests indicates that the dispersants of
the invention enable inks to be prepared in a range of polymeric binders
producing good tinctorial properties.

[0132]Each of the documents referred to above is incorporated herein by
reference. Except in the Examples, or where otherwise explicitly
indicated, all numerical quantities in this description specifying
amounts of materials, reaction conditions, molecular weights, number of
carbon atoms, and the like, are to be understood as modified by the word
"about". Unless otherwise indicated, each chemical or composition
referred to herein should be interpreted as being a commercial grade
material which may contain the isomers, by-products, derivatives, and
other such materials which are normally understood to be present in the
commercial grade. However, the amount of each chemical component is
presented exclusive of any solvent or diluent oil, which may be
customarily present in the commercial material, unless otherwise
indicated. It is to be understood that the upper and lower amount, range,
and ratio limits set forth herein may be independently combined.
Similarly, the ranges and amounts for each element of the invention may
be used together with ranges or amounts for any of the other elements.

[0133]While the invention has been explained in relation to its preferred
embodiments, it is to be understood that various modifications thereof
will become apparent to those skilled in the art upon reading the
specification. Therefore, it is to be understood that the invention
disclosed herein is intended to cover such modifications as fall within
the scope of the appended claims.